The Hemline Index — the notion that hemlines rise during economic upswings, and head towards the floor in downturns — is still kicking around. And for no good reason, frankly, because it's an unreliable indicator of anything beyond fickle fashion trends. And yet it persists, year after year, season after season. What is it that makes the hemline index such a popular myth, and what does its enduring power say about how we view women's economic activity?

Business Insiderthis season proved that, on average, the New York designers showed shorter skirts and dresses for fall 2012, compared with those they showed for fall 2011. It did this by looking at photos of every runway look presented by 25 top women's wear brands, including Marc Jacobs, Jason Wu, J. Crew, and Michael Kors:

The BI Hemline Index is calculated by measuring hem length as a percentage of the length from floor to waistline. The shorter the hemline, the higher the index. Overall, average hemlines in 2012 registered a 44.38 on the index, up from 35.04 for the Fall/Winter 2011 collections. Complete looks from each designer were measured, however skirts and dresses were the only data points fed into the data set. Measurements were taken from images provided post-show.

Okay. Hems on average got shorter this season. Good job! Someone's eyes work. But what Business Insider has not proved is that hemlines have any relationship whatsoever with the overall economy. That assertion — that the so-called Hemline Index is actually, you know, real, or as Business Insider put it in its headline, "Skirts Are Getting Shorter And That's Bullish For The Economy" — is a belief that goes unexamined in the piece.

There are a number of problems with the "hemline index." For one, it represents a misunderstanding of the fashion industry on multiple levels. The first and most obvious problem is that designers no longer "set" hemlines. The time when American women were simply waiting for Big Fashion to tell them "how high" — if that time ever really existed — ended long ago. Fashion critics haven't been dispatched to the shows to find "the" hemline since the early 1970s, and fashion editors do not sit around conspiring to make the American public Think Pink (or to Think Miniskirts).

In any given season, different designers will present different ideas of what they think is modern and original (or, more cynically, of what they and their respective subscription trend-forecasting services believe will be commercially desirable in six months' time). The runway is a hopper into which many incipient trends are fed. Hems on the catwalk will be low, high, midi, mini, maxi, calf, handkerchief, mullet — you name it, someone will show it. And what women will actually choose to wear when the seasons change? That depends on even more variables. For the hemline index to be real, or even possible, there would have to be A Hemline. But there isn't.

That much is evident even in the photographs Business Insider chose to illustrate its story — which depict all kinds of hemlines. A sizable minority of the designers BI chose to focus on (including highly influential names like Alexander Wang, Donna Karan, and Carolina Herrera) actually showed skirts and dresses that were on average longer than those they showed last year. Fashion design just isn't about handing down a "new" skirt length from on high. (Besides, I hear a lot of women wear pants these days.)

But even in the days when fashion was a more hierarchical industry, when you could tell last season's skirt from this season's by its length and silhouette, hemlines had no predictive value to the wider economy. The hemline index has been extensively studied and debunked by academics. Most recently and perhaps most comprehensively, Marjolein van Baardwijk and Philip Hans Franses of the Erasmus School of Economics made a note of the lengths of skirts that appeared in the French fashion magazine L'Officiel every month from 1921-2009. They found that skirt lengths "have no predictive ability for the state of the economy." (Yes, that sentence had to be written in a journal article. Despite the fact that believing shorter skirts foretell better economic conditions is, if you think about it for about, oh, a half a second, the economic equivalent of believing those Iranian clerics who hold that women's skimpy clothing causes earthquakes.)

Blogger Jen McCreight has proposed that, on April 26, women worldwide don their most immodest tops…
Read more Read more

The persistently alleged correlation between women's skirts and macroeconomic performance is not the only dubious fashion-related indicator spawned by the world of pop-econ. There's also the "lipstick index" (women buy more lipstick in a recession; false), the "manicure index" (women either get more salon manicures during a recession or they buy more drugstore nail polish to do it themselves — the sages can't seem to decide which it is; that alone should tell you this one is not true), and the "heel height index" (women buy higher heels in a recession, because platform shoes were invented during the Great Depression; they don't, and they weren't).

As Autumn Whitefield-Madrano wrote last year, these economic indices have one other thing in common, besides their unreliability: they focus on women's consumption. "The repeated 'whoda thunkit?!' tone," of these news stories, wrote Whitefield-Madrano, "began to feel belittling, like, Aw, so cute, she's got a coincident countercyclic economic indicator in her Hello Kitty makeup bag!"

When I first heard of the lipstick index—a term coined by Estee Lauder chairman Leonard Lauder to…
Read more Read more

Things like the lipstick index are appealing for those of us who aren't particularly schooled in economics. It's handy to have the complexity of the economy handed to us in a digestible form: the burger index! the underwear index! It makes us feel like our little habits might add up to something bigger. I particularly wanted my lipstick-my silly, frivolous little lipstick-to mean something "real."

What I hadn't seen was that the continued emphasis on the lipstick index — or the manicure index, or the hemline theory — actually made women's purchasing power seem more trivial, not less. The more we examine what women buy, the more we're keeping them in their place.

The lipstick index, the hemline index — and more importantly, our continued collective interest in generating and consume "news" stories, blog posts, and TV segments that present these and the other aforementioned debunked hypotheses as fact — have always said more about certain cultural ideas we have about women and shopping than they have about the economy.

As Gaby Hinsliff argues in the New Statesman, the common view of women as economic consumers (shoppers) instead of economic producers (workers) can be pernicious. Not least because these stories displace and obscure fuller, more accurate assessments of women's economic impact:

The dangerous thing about this idea is that it can obscure women's role in creating rather than frittering wealth. What you don't hear so often is how western economic growth has been boosted by the shift of women, and especially mothers, into work since the 1970s. By 2009, the American economy was up to 25 per cent bigger than it would have been had millions more women not chosen over the previous four decades to work, according to figures cited by the management consultants McKinsey. That kind of growth isn't just down to women having more money to buy shoes.

The other way in which the hemline index misunderstands fashion is simple: in seeking to look for an "unexpected" economic indicator in fashion, these reporters are missing the fact that fashion itself is an economic indicator. Fashion, not even counting retail, is one of New York City's largest industries — fashion week alone, in just 14 days of the year, is projected to generate $865 million in economic activity in New York City. (That's nearly $100 million more than in 2007: how's that for an economic indicator?) The industry as a whole is worth billions to the national economy.

There is simply no need to assign basis points to mini-skirts and go hunting for secret messages about the economy in the hemlines in order to give fashion — that domain of women, gay men, and the chiffon they love — some economic weight. Fashion as an industry has an economic impact all of its own. It could, however, benefit from the attentions of some diligent financial reporters (just consider for a second the differences between how fashion is reported on versus how New York's other great industry, finance, is covered). Perhaps Business Insider would like to volunteer?